THURSDAY, June 17 (HealthDay News) -- For Botox users concerned that the muscle-paralyzing injections will rob their face of its ability to show emotion, a new study suggests that people injected with the toxin might end up with less strong emotion to display in the first place.

Researchers at Barnard College in New York City found that facial expressions appear to play a role in how your emotions develop, not just in how you display them for others to see.

The study suggests that facial expressions themselves may influence emotional experiences through a kind of feedback loop. In short, Botox -- a toxin that weakens or paralyzes muscles -- not only changes one's appearance, but also appears to deaden real emotions.

"In a bigger picture sense, the work fits with common beliefs, such as 'fake it till you make it,'" study co-author Joshua Davis, a psychology professor at Barnard College, said in a school news release. "With the advent of Botox, it is now possible to work with people who have a temporary, reversible paralysis in muscles that are involved in facial expressions. The muscle paralysis allows us to isolate the effects of facial expression and the subsequent sensory feedback to the brain that would follow from other factors, such as intentions relating to one's expressions, and motor commands to make an expression."

Davis explained that "with Botox, a person can respond otherwise normally to an emotional event, e.g., a sad movie scene, but will have less movement in the facial muscles that have been injected, and therefore less feedback to the brain about such facial expressivity. It thus allows for a test of whether facial expressions and the sensory feedback from them to the brain can influence our emotions."

The study was published in the June issue of the journal Emotion.

More information

For more on Botox, visit the U.S. National Library of Medicine.